Method of grading ores or similar materials



(No Model.)

D. BRENNAN,'J1-. METHOD OF GRADING ORES 0R SIMILAR MATERIALS.

I Patented Nov. 26, 1894.

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W/TNESSES."

ATTORNEYS.

THE-NORRIS PETERS c0, FNOTD-UTHQ. WASHINGTON u. c.

UNITED STATES PATENT ()FFICE,

DANIEL BRENNAN, JR, OF BAYONNE, NEW JERSEY.

METHOD OF GRADING ORES OR SIMILAR MATERIALS.

SPECIFICATION forming part of Letters Patent No. 529,587, dated November20, 1894. Application filed November 3, 1893i Serial No. 489,896- (Nomodel.)

T0 and whom it may concern.-

Be it known that 1, DANIEL BRENNAN, J r., of Bayonne, in the countyof-Hudson and State of New Jersey, have invented a new and ImprovedMethod of GradingOres or Similar Materials, of which the following is afull, clear, and exact description.

Theinvention is designed mainly to classify ores comminuted so finely asto be extremely difficult and expensive to classify by screens, it beingwell known that below a certain fineness screens are impracticable onany large commercial scale.

In grading comminuted ores, sand and similar material in accordance withmy invention,the materialisfed in the form of aclose, continuouslyfalling stream, into a chamber containing a fluid, such as air or water,and the force of gravity is utilized, as hereinafter particularlyexplained, in effecting a separation of the finer and lighter particles.from the coarser and heavier ones, the conditions to be observed forsuccess being the initial compactness and volume of the stream, thedensity of the fluid medium, the extent of fall of the material, and theexpansion permitted the stream or column of material be fore dividing orarresting the same. The stream being initially of the proper volume andcompactness, as it falls through the fluid, a continuous re-arrangemontof the particles will take place, the stream tending to becomedisintegrated, and as the stream progresses an outward whirling orcurling movement will be induced at the exterior of the column and theexpansion of the latter becomes more marked, until a point is reachedwhere the particles range themselves with the lightest and finest at theexterior of the now pronouncedly widened column,and increasingly coarserand heavier toward the initial line of fall. At this point 1 divide thecolumn of material, by separating the outer particles from those nearerthe initial line of fall, while continuing the feed, and if desired Imay also effect any desired practical subdivisions.

Reference is to be had to the accompanying drawing'forming part of thisspecification, in which is shown in perspective, the preferred apparatusfor carrying out my invention, the front wall or side being omitted toshow the interior.

The case A, is preferably rectangular and of a height. to allow thematerial considerable of afall, the fluid medium being air. At the topof the case A a hopper B, is provided,

the delivery orifice or opening 'of which is at about the center of thecase, and is narrow but elongated, to feed a narrow stream extendingsubstantially across the full width of the case in one direction. Theparticular form of the orifice will, however, vary in practice. One wallor side a of the hopper is fixed, while the other wall or side I) ishinged as at b, and is adapted to'be adjusted toward and from theopposite fixed wall by means of a screw rod b At the bottom of theapparatus, fixed vertical partitions O, O, are provided forming acentralpocket and two side pockets, each of which is provided with anoutlet as at c, which may be closed in any suitable manner to permitoutlet of the material as desired without causing any considerablemovement or currents of the fluid within the case. On the top of each ofthe partitions O, is a movable partition O, which is mounted on a rockshaft 0', and these rock shafts extend through and beyond the front sideof the case, and outside of the case the shafts receive arms D, to theopposite ends of which there are pivoted the threaded rods D, whichextend upwardly through slots in the brackets d on the case, andreceive, above the brackets, the hand wheels 01', thearrangement beingsuch that by turning the hand wheels the movable partitions U, may beadjusted toward and from each other, and also independently of eachother. By this means the entrance to the central pocket may be made toalign with the center of the stream, should the line of fall shiftslightly by the settling of a floor The fluid in the case should besubstantially inert for the best results, that is, it should have nomovement other than that induced by the falling material, or that wouldaffect the widening of the column and the arrangement of thecontinuously falling particles, so that by dividing the falling column,the separation of the fines may be effected.

The apparatus shown, While it is the preferred form,is not absolutelyessential to the carrying out of my improved method, and may bemodified, it being only essential that the stream be permitted toprogress undivided, under the influence of gravity, a sufficientdistance, and permitted to disintegrate and expand or widen whilefalling, and before being divided or arrested, until the particlesarrange themselves increasingly coarser and heavier from the outsidetoward the center or initial line of fall or practically so, whereby aproper vertical division of the column will cut off the required finesfrom the coarser and heavier particles. Some fines may be held among thecoarser particles until the movement induced becomes too weak to detachand deflect them to the outside, and a second operation will then benecessary if it is desired to recover them, but with a proper falland aproper adjustmentof the partitions the particles will, to a practicaldegree, arrange themselves increasingly larger from the outside towardthe center, and enable a good practical separation to be effected.

Having thus fully described my invention, I claim as new and desire tosecure by Let ters Patent- The herein described method of gradingcomminuted ores and similar materials, consisting in causing thematerial to fall, in response to gravity, in a stream of unscatteredparticles, in a fluid medium,while maintaining the medium undisturbedexcept as movement thereof is induced by the particles responding to theforce of gravity, permitting the stream to thus progress downward,unobstructed, and to expand until a self grading of the stream iseffected and the particles range themselves to a practical degree,increasingly coarser from the exterior toward the line of initialvertical fall, and then separating the expanded stream into grades bydividing the same, substantially as described.

DANIEL BRENNAN, JR.

Witnesses:

F. W. HANAFORD, O. SEDGWICK.

